Means for arresting motion of electric cars



2 SheetsSheet 1.

W. C. ANDERSON. MEANS FOR ARRESTING MOTION OF ELECTRIC CARS.

(No Model.)

Patented Mar. 8,1898.

\JUUUN-ILJU (No Model.) 2 Sheets-Sheet 2.

-W. 0. ANDERSON. MEANS FOR ARRESTING MOTION 0F ELECTRIC CARS.

N0. 600,252. Patented Mar. 8,1898.

WITNESSES:

UNITED STATES PATENT OFFICE.

\VILBUR O. ANDERSON, OF \VEST HOBOKEN, NE'XV JERSEY.

MEANS FOR ARRESTING MOTION OF ELECTRIC CARS.

SPECIFICATION forming part of Letters Patent No. 600,252, dated March 8, 1898. Application filed Augu t 30, 1895. Renewed October 23, 1897. Serial No. 656,194. (No model.)

To ctZZ whom it may concern:

Be it known that I, WILBUR G. ANDERSON, a citizen of the United States, residing at West Hoboken, in the county of Hudson and State of New Jersey, have invented certain new and useful Improvements in Means for Arresting the Motion of Electric Cars, of which the following is a full, clear, and exact description.

This invention relates to means for retarding the motion of electrically-propelled cars through the agency of their propelling motor or motors. The principle employed is that of converting the motors into generators and consuming the momentum of the car in drivin g the generators upon a closed short circuit.

The object of my invention is to provide means whereby this manipulation of the propelling motor or motors may be accomplished with simple and inexpensive mechanism and by mechanism which is easily applicable to the standard apparatus now in use and which Will require the motorman in charge of the car to make only those movements to which he is accustomed in the ordinary control of the car.

It has been the practice with motormen in emergencies to stop the car by reversing the motors. To accomplish this, it is first necessary to cut off the supply of current by the movement of one lever, then reverse the reversing-switch by another movement, and, finally, turn on the current again by a movement of the first lever. This, it will be seen, requires three movements, and even then the action of the motors is often too slow to avoid the impending accident. Furthermore, this operation requires constant connection with the source of current, and if the traveling contact which supplies the car should become disconnected with the feeding-conductor this method of stopping would not be possible. By my invention the only movements which the motorman makesare the first two above mentioned-to Wit, cutting 01f the supply and throwing the reversing-switch. In some instances also, as will be hereinafter pointed out, it is only necessary to make the first movement-to wit, cutting 01f the supply. Thus by my invention the motor-man is called upon only to perform such operations as he is well accustomed to, and he is not liable to become confused in emergencies where the invention is designed to be utilized.

My invention consists in establishing a bridging-circuit and suitable switching apparatus to be used in combination with the regular car-switching apparatus in the manner hereinafter described.

The invention will be described in detail with reference to the accompanying drawings, in which Figure 1 is a diagram of the circuits and apparatus used upon a car propelled by two motors which may be controlled from either platform of the car, the method of controlling being known as the series parallel. This diagram also embodies the features of my invention. Fig. 2 is a similar diagram of circuits, showing a different construction and location of the switches necessary in carrying out my invention. Fig. 3 isasimpler diagram showing the circuits more graphically.

The two propelling-motors are represented by A A, respectively. The controlling-cylinder at one end of the car is represented by O and the reversing-cylinder by R. The controlling-cylinder at the other end of the car is represented by O and the reversing-cylinder by R. It will be understood that the controlling-cylinders are used to turn on and turn off the current of the motors and to vary the speed of the car, while the reversing-cylinders are used merely to change the direction of travel of the car. The diagram shows the controlling-cylinders with only two rows of contact-points c 0, respectively. Then these two rows of contacts are connected with the fixed terminals d, the motors are connected in series or in parallel. The ordinary controlling cylinder is also provided with other rows of contacts for controlling the resistances, &c.; but it is deemed unnecessary to show these contacts here. The rows of contacts on the reversing-cylinders are shown complete as ordinarily used. To these ordinary swit-ching-cylinders are attached the switching apparatus S and S, described as follows: On the lower edge of the reversingcylinder I place three contact-plates e, e, and c and adjacent to the cylinder I mount in any suitable manner four stationary contactlingers 1 2, 3, and 4:. These are so arranged that the circuit from 1 to 2 is always closed either through plate 6 or plate c and the circuit from 3 to t is always closed either through plate s or plate 6 except when the reversingcylinder is at the off position-that is,when neither of its rows of contact-points is in connection with the stationary terminals g. On the controller-cylinder two conducting-plates f and f are fixed, and suitably mounted adjacent thereto are the four contact-fingers 5, 6, 7, and S. \Vhen the controlling-cylinder is at the off position--that is, when the trolley or source of supply is disconnectedthe stationary fingers are in contact with the plates and the circuit from 5 to 6 is closed and also from 7 to 8. At all other times the circuit between these two pairs of fingers is open.

The circuits can best be traced in the statement of the operation, which is as follows: WVe will assume the car to be moving forward with the motors in series, under which condition the contacts 0 of the controlling-cylinder will be in connection with the terminals (Z and the contacts 7 of the reversing-cylinder will be in connection with the terminals g. The trolley-current enters wire 9, thence flows over the following course: wire 10 to the controlling-eylinder, wire 11 from the controlling-cylind er, resistance R wire 12 to the point 13, thence by wire 14 to the reversingcylinder, wire 15 from the reversing-cylinder, wire 16 through the armature of motor A in the direction of arrow :10, wire 17, wire 13 to the reversing-cylinder, wire 19 from the reversingcylinder, wire 20 through the field-magnet of motor A,wire 21 to the point 22, thence by wire 23 to the controlling-cylinder,wire 24: from the controlling-cylinder, wire 25, wire 26 to the reversing-cylinder, wire 27 from the reversingcylinder, wire 28 through the armature A in the direction of arrow 3, wire 29, wire 30 to the reversing-cylinder, wire 31 from the reversing-cylinder, wire 32 through the magnet of motor A, and finally to ground at G. The branches leading from the points 13 and 22 and from the wire 24: are Open-circuited at the switch S on the controlling-cylinder. There fore the current would not flow in that direction. Now suppose it becomes necessary to stop the car very suddenly. To accomplish this, the motorman will cut off the trolleycurrent by throwing the controller C to the off position. This will close the switch S. He then throws the reversing-cylinder to the point where the row of contacts 7" will be in connection with the terminals g, which movement is the same as that used ordinarily to reverse the car. In doing this the plates 6 and e and e of switch S are shifted with respect to the terminals 1, 2, 3, and 4:; but the circuit through each pair of terminals still remains closed. We now can trace the following circuit, the motors being driven by the momentum of the car and the relation between the field-magnet and armature having been reversed by the movement of the reversing-switcl1,the motors become generators,

and the current will leave the armature and brush where it formerly entered: Commencin g with motor A (now generator) the current is traveling through its armature in the direction of arrow y, thence by wire 16, wire 15 to the reversing-cylinder, wire 19 from the reversing-eylinder, wire 20 through the fieldmagnet of generator A, wire 21 to the point 22, wire 33, switch S, wire 34:, switch S, wire 35, wire 25, wire 26 to the reversing-cylinder,

, wire 30 from the reversing-cylinder, wire 29 through armature of generator A in the direction of arrow '6, wire 23, wire 27 to the reversing-cylinder, wire 31 from the reversingcylinder, wire 32 through the magnet of generator A to the ground G, thence from ground at G by wire 36, switch S, wire 37, switch S, wire 38 to the point 13, wire 14 to the reversing-cylinder, wire 18 from the reversing-cylinder, wire 12, and into the armature of generator A. Thus it will be seen that the motors are now in a closed local circuit of so small a resistance that they are practically short-circuited, and as the relation between the field-magnet and armature of each machine was changed without changing the direction of rotation the machines act as generators, their field-magnets quickly building up and offering a very great resistance to the forward movement of the car. The car therefore quickly comes to a stop if it be on a level, and if on a downgrade it merely creeps at a very slow pace.

Now in case the car happens to be moving up a grade and the mechanical or other brake on the car does not work when a stop is made the motorman simply throws his controllingeylind er to the off position. This will prevent the car traveling at more than a creeping pace backward down the grade, because the direction of rotation of the motors will be reversed, and this when the motors are generators is the equivalent of reversing the fieldmagnet and armature relation.

The object of providing two switches S and S is to prevent interference of the circuits when the motorman leaves one end of his car and goes to the other. Before the motorman makes this change he always throws both the controlling and reversing cylinders to the off position. This closes the circuit of switch S, and if there were not a break at some other point in the circuits which this switch controls there would be an interference between the circuits running, respectively, to the two ends of the car. This second break is therefore provided for by the switch S, which is opened only when the reversing-cylinder is at the off position.

It is of course obvious that my invention comprehends the equivalent of the switches S and S whether they be attached to the controlling and reversing cylinders or not. The

switch S on the reversing-cylinder being always closed when in operating condition may be regarded as an unnecessary element, and the switch S is not necessarily located upon the controlling-cylinder. If desired, it may I ture of motor A, (in opposite direction,) rebe made entirely independent thereof. Then in operating the device the motorman would first throw the controlling-cylinder to the off position and then manipulate the independent device, whatever it may be, to close the switch S. The function of the switch S is merely to put the stopping or braking circuit into condition for the manipulation of the reversing-cylinder to stop the car. It may therefore be operated by a separate handle attached to any part of the controller or at any point on the car within reach of the motorman. If only one controller is on the car, the switch S will be entirely dispensed with.

This invention also has the advantage of being applicable to most any form of car-controlling apparatus, and particularly it is not limited to controllers having reversing apparatus of the character above described, and illustrated in Fig. 1. In Fig. 2 I have shown an entirely different form of reversing-switch and an arrangement of circuits and apparatus adapted thereto, something of this character being now commonly in use. This will now be described. WVherever the same reference letters and numerals are used, they are applied to the same parts. In this case the reversing-cylinders are substituted by ordinary three-point switches m and m, which are operated mechanically from either end of the car by means of a rod n or other suitable de vice. The switches may be located anywhere upon the car. I11 this instance the switches S are dispensed with, their functions being performed by the switches S and S on the respective controlling-cylinders, which act complementary to each other. Switches S and S are closed only when the cylinders are at the off position. The switch at the rear end of the car is therefore always closed, and to put the braking-circuit into operation it is only necessary to close the switch at the forward end.

Let us'suppose the car to be running in the direction of arrow M and the motors are in series. The contacts 0 will then be connected with terminals cl, and the circuit will be as follows: from trolley by wire 40 to the controller, wire 41 from controller, field-magnet of motor A, wire 42, reversing-switch m, armature of motor A, reversing-switch m, wire 43 to controller, wire 44 from controller, field-' magnet of motor A, wire 45, reversing-switch m, armature of motor A, reversing-switch m, wire 46 to ground at G. To apply the brake, controlling-cylinder is thrown to the off position, thus closing its switch S, the other switch S being already closed. Then the reversing-switches are thrown, and we have the following circuit: Beginning at armature of motor A current travels in opposite direction and flows to reversing-switch m, thence by wire 43, wire 47 to switch S on controller 0, wire 48 to switch S on controller 0, wire 49, wire 50, wire 44, field-magnet of motor A, wire 45, reversing-switch m, armaversing-switch m, wire 46 to ground at G, thence from ground at G to switch S on controller O, wire 51, switch S on controller 0, wire 52, wire 53, wire 41, field-magnet of motor A, wire 42, reversing-switch m, and back to armature of motor A. This complete circuit includes the two motors, the two reversing-switches, and the two switches S and S in series. The motors then act together as generators and quickly retard the car. If the car were running away downhill, the reversing-switch would not be thrown for the reason before described.

In case a car is equipped with only one motor it is of course obvious that the invention will operate in the same manner-that is to say, one motor may be short-circuited as readily as two. The wire 0 in Fig. 3, which represents the bridging-circuit, may be utilized just as easily when one motor is used as when two motors are used.

Other brakes involving the principle herein utilized have been proposed and patented, but the apparatus adopted has been expensive to apply to existing types of electric cars or they did not accomplish all that was necessary. One of the merits of my plan is the facility and cheapness with which it may be applied to or combined with the mechanism of the cars now in use. In the second plan (shown in Fig. 2) it is only necessary to run two wires from one end of the car to the other and insert the circuit-openers S and S therein. These circuit-openers may be of similar construction and are easily applied to the controllers. In the first form, Fig. 1, short wires are run from the proper terminals in each controller to the switches S and S,which also are of simple construction and easily applied.

Having described my invention, I claim- 1. In an electric car, a local circuit including the motor or motors and the reversing switch or switches, two car-controllers, two circuit closers or switches one operated by each controller, the contacts on the controller and on the switches being so arranged that when the main source of current is cut off from the motors the switches are closed completing the local circuit, substantially as described.

2. In an electrically-propelled car, the combination of the propelling motor or motors, a short local circuit, a car-controlling device at each end of the car, a cut-out or switch corresponding to each car-controlling device, said cut-out or switch being automatically closed when its corresponding controlling de vice opens the main circuit to the motor or motors and open when the main circuit is closed, said short local circuit including the motor or motors and the two out outs or switches, said cut-outs being in series with each other.

3. In an electrically-propelled car, the combination of the propelling motor or motors, a

short local circuit, a car-controlling device at each end of the car, a cut-out or switch corresponding to each car-controlling device and a reversing-switch, said cut-out or switch being closed when its corresponding controlling device opens the main circuit to the motor or motors, and open when the main circuit is closed, said short local circuit including the motor or motors, the car-reversing switch and the two cut-outs or switches, said cut-outs beinc; in series with each other.

4;. In an electric car, a propelling motor or motors, two controllers by which the current can be fed to the motors, a reversing, switch or switches, a local circuit including the motor or motors, the reversing switch or switches, and two switches or circuit-controllers, the said switches or circuit-controllers being in series with each other and actuated to auto- \VILBUR O. ANDERSON.

Vitncsses:

FRANK S. OBER, JOHN KEALGER. 

